Numerical Recipe headers and functions can be added here. These headers and functions can be found at https://numerical.recipes/. If necessary, they can easily be replaced by equivalent functions from the GNU Scientific Library (GSL) that can be found at https://www.gnu.org/software/gsl/.

This is a list of the headers and functions used:
golden.cpp
nr.h
nrtypes_nr.h
nrtypes.h
nrutil_nr.h
nrutil.h
ran1.cpp
ran2.cpp